#define _CRT_SECURE_NO_WARNINGS 1
/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
//class Solution {
//public:
//    int maxDepth(TreeNode* root) {
//        if (root == nullptr) return 0;
//        int heightleft = maxDepth(root->left);
//        int heightright = maxDepth(root->right);
//        return heightleft > heightright ? heightleft + 1 : heightright + 1;
//
//    }
//};